A dependable source of potable water eludes vast segments of humanity, the Canadian International Development Agency reporting that about 1.2 billion people lack access to safe drinking water. A person must depend, for a supply of clean water, on proximity to uncontaminated natural sources, or must otherwise have access to a dependable common system of publicly treated water, or else dependable supplies of chemical purifying agents or power sources for distillation, none of which are typically available in much of the developing world. Consequently, an integral and reliable source of treating water, whether for medical purposes, for human consumption, or otherwise, that is robust, efficient, and requires only readily available materials is very desirable. As used herein, and in any appended claims, the term ‘purifying’ refers to substantially reducing the concentration of one or more contaminants to specified levels or otherwise substantially altering the concentration of one or more substances to specified levels. The term ‘specified levels’ refers to some desired level of concentration, as established by a user for a particular application. One instance of a specified level may be limiting a contaminant level in a fluid to carry out an industrial or commercial process. An example is eliminating contaminant levels in solvents or reactants to a level acceptable to enable an industrially significant yield in a chemical reaction (e.g., polymerization). Another instance of a specified level may be a certain contaminant level in a fluid as set forth by a governmental or intergovernmental agency for safety or health reasons. Examples might include the concentration of one or more contaminants in water to be used for drinking or particular health or medical applications, the concentration levels being set forth by organizations such as the World Health Organization or the U.S. Environmental Protection Agency.
Distributed water purification systems, such as described in U.S. Provisional Application 60/425,820 and concurrently filed U.S. application Ser. No. 10/713,617, entitled “Pressure Vapor Cycle Liquid Distillation, and distributed electrical generators, such as diesel-powered internal combustion generators and generators based on the Stirling cycle, such as described in U.S. Pat. No. 6,253,550, may be used to provide electricity and safe drinking water without the expense and delays associated with building and maintaining utility plants and the infrastructure required to bring the electricity and safe drinking water and to its point of use. With the use of such distributed utilities, however, comes the need to appropriately distribute these utilities to the people who need them and to monitor the operation and correct usage of these systems.